Power operated chair with fluid brake



Jan. 25, 1966 c. 1.. REDFIELD 3,230,714

POWER OPERATED CHAIR WITH FLUID BRAKE Filed Dec. 26, 1963 5 Sheets-Sheet 1 E O E 2: LL] 0:

m J W5 6 1 I 0 LL INVENTOR.

CHARLES L REDFIELD ATTORNEYS c. L. REDFIELD 3,230,714

POWER OPERATED CHAIR WITH FLUID BRAKE 5 Sheets-Sheet 2 Jan. 25, 1966 Filed Dec. 26, 1963 Ull I WM RI I 'i/IH O FIG-5 INVENTOR. CHARLES L. REDFIELD AT TO RNEYS Jan. 25, 1966 c. REDFIELD 3,230,714

POWER OPERATED CHAIR WITH FLUID BRAKE Filed Dec. 26, 1963 5 Sheets-Sheet 3 INVENTOR. CH ARLES L REDFIELD ATTORNEYS Jan. 25, 1966 c. L. REDFIELD 3,230,714

POWER OPERATED CHAIR WITH FLUID BRAKE Filed Dec. 26, 1963 5 Sheets-Sheet 4 OUTLET I ;F 50a |ON v I LQCK RIGHT HAND ARM |SWITCH LOFF SEAT PLATE CHAlR CIRCUIT 602i 5 LEFT HAND ARM OUTLET INVENTOR. CHARLES L. REDFIELD m zmz w ATTORNEYS Jan. 25, 1966 c. REDFIELD 3,230,714

POWER OPERATED CHAIR WITH FLUID BRAKE Filed Dec. 26, 1963 5 Sheets-Sheet 5 BRAKE 5O swwcy/ w--.{j],- N.C 55 00- :O NO. 2 STEM r- 1 RELAY,

0 0 POWER SUPPLY 53 T I' BULKHEAD 36 a i u DUAZF VALVE RESERVOIR M s L A -JL I 31 L .i" 37 BASE CIRCUIT INVENTOR.

CHARLES L. REDFIELD ATTORN EYS United States Patent 3,230,714 POWER OPERATED CHAIR WITH FLUID BRAKE Charles L. Redfield, Downers Grove, 111., assignor to Emil J. Paidar Company, Chicago, 111., a corporation of Delaware Filed Dec. 26, 1963, Ser. No. 333,299 9 Claims. (Cl. 60-52) The present invention relates to improvements in rotatable and elevatable chairs such as used for barber chairs and particularly to a power operating mechanism and a brake for locking the chair against rotation.

In a power operated chair such as a barber chair, it is important from the standpoint of the barber shop operator and from the standpoint of the manufacturer that the chair be capable of continuous operation over many years without attention or adjustment since the installations are frequently made where replacement or repair is impossible, and such repair it undesirable from the standpoint of continued satisfactory operation without loss of time or use of the chair. These operations include satisfactory elevation and lowering of the chair and controlling the rotation of the chair by either permitting free rotation or by obtaining positive locking against rotation, and also against settling or lowering of the chair. Where locking of the chair is accomplished it is imperative that the lock be released when the chair is being raised or lowered so that diiferent power mechanisms are not operating against each other to cause damage or breakage of parts. It is also important from the standpoint of the shop operator and the customer that elevation and lowering of the chair and locking be accomplished with maximum smoothness and the elimination of jars and shocks, and with a minimum amount of noise. It is also essential that the power mechanized parts not be overstressed or overtravelled so that when the chair reaches the limit of its elevation, for example, it automatically stops without damage to mechanism.

An object of the present invention is to provide an improved power operated chair well suited for use in barbering or other similar power chair operation, wherein the mechanized parts are constructed and function with improved interrelation which insures their long operating life and reliability and insures optimum ease of control by the shop operator.

A further object of the invention is to provide an improved locking mechanism which positively prevents rotation of the chair and also prevents inadvertent lowering, and in which mechanical assurance is incorporated that prevents the chair from inadvertently remaining locked when power operated elevating mechanism is turned on.

A further object of the invention is to provide an improved hydraulically operated locking mechanism which operates through the same hydraulic system as the hydraulic elevating mechanism and which is automatically operated to brake the chair in locked position when other mechanism is not operating and which automatically releases when other operating mechanism for the chair is operated.

A further object of the invention is to provide an improved chair which has electrical power accessible on the chair, even though the chair is rotatable and elevatable, and wherein the electrical outlets are automatically deenergized with operation of electrical power elevating mechanism.

A still further object of the invention is to provide an improved power operated chair with travel limiting features which limit the elevation of the chair and operate mechanism in a safe foolproof manner.

A still further object of the invention is to provide an improved hydraulically releasable normally locked brake for preventing rotation of the chair.

ice

Other objects, advantages and features will become more apparent with the teaching of the principles of the present invention in connection with the disclosure of the preferred embodiments thereof in the specification, claims and drawings, in which:

FIGURE 1 is a side elevational view of a chair of the type embodying the principles of the present invention;

FIGURE 2 is a schematic view of a chair control and operating mechanism constructed in accordance with the principles of the present invention;

FIGURE 3 is a perspective view of the brake of the present invention;

FIGURE 4 is an exploded detailed view of the brake;

FIGURE 5 is a top plan View, with portions in section, of the brake; and

FIGURES 6 and 7 are wiring diagrams, to be viewed together, showing the electrical control arrangement for the mechanism.

As shown on the drawings:

As illustrated in FIGURE 1, a barber chair 10 is supported on a base 12 on a power elevating mechanism indicated generally at 13. The chair has a seat 14, arm rests 15, a back 16 and a head rest 17. Below the seat in front is a foot rest 13, and an operating arm 19 is provided for controlling the chair. The operating arm 19 is suitably connected to switch mechanisms for either elevating or lowering the chair and for rotationally locking or unlocking the chair. Switches may be substituted for the arm 19 although the arm is preferred in certain installations since it simulates mechanical operating mechanism to which the chair operator has become accustomed and it is desirable for that reason.

The operating mechanism for elevating and lowering and locking the chair is shown in FIGURE 2 schematically, with a chair plate 20 provided upon which the chair 10 will be bolted. The chair plate is maintained horizontal for maintaining the chair 10 in its proper upright position by suitable bearings and guides, not shown, and is elevated by a piston 22 slidable within a cylinder 21 and having a piston rod 23 connected to the chair plate 20.

Hydraulic fluid is delivered into a chamber 24 beneath the piston 22 to cause the piston to slide upwardly in the cylinder and thus elevate the chair.

Depending downwardly from the chair plate is a tube 25 which may afford the stabilizing and guide means for maintaining the chair upright, and the tube has a cylindrical outer surface sliding within bearing supports or guides 25a. The tube also afiords a means for locking the chair against rotation by a brake 26. The brake is anchored to the base 12 shown schematically at 27. The brake is normally held locked, and is released by hydraulic piston and cylinder shown generally at 28, with spring clamping elements at 29 maintaining the brake normally locked. These elements are shown in greater detail in FIGURES 3-5.

For raising the chair, hydraulic fluid is delivered from a pump 30 driven by a motor 31 and fluid is obtained from an oil reservoir 38. Fluid is simultaneously delivered to a chair elevating line 32 and a brake release line 33. As will be observed from FIGURE 2, the hydraulic fluid delivered through line 32 will raise the piston 22 and when the pump is stopped fluid will be prevented from being returned to the pump through a check valve 34. Fluid delivered to the brake release mechanism 28 is prevented from returning to the pump by a check valve 35 in the line 33. Thus, when the chair is elevated and the pump 30 stopped, the chair stops at its elevated position and the brake remains unlocked.

For lowering the chair a dump valve 36 is opened.

For applying the brake a brake release valve 37 is opened. The dump valve 36 and brake release valve 37 are electrically operated from the chair and their connection in the circuits provided will be described relative to FIGURES 6 and 7.

The brake 26 is shown in detail in FIGURES 3-5 and includes a band 42 with a Smooth inner cylindrical surface and ends 46 and 41. The band 42 is of spring-like material so that when the ends 40 and 41 are moved toward each other the band is clamped tightly around the cylindrical outer surface of the tube 25, FIGURE 2,, to positively hold the tube against rotation and thereby hold the chair. When the ends 40 and 41 of the band are separated or pushed apart, the tube is released so that the chair can be rotated. For anchoring the band an opening 27!) is provided at its base with a pin 27 in the opening flanged over at its inner end 27:: so that the pin can be suitably anchored to supporting mechanism mounted on the chair base.

The ends 40 and 41 of the band carry blocks 43 and 46. The block 43 has a cylindrical chamber 44 in which is slidably mounted a piston 47. The piston is shown as snugly fitted within the cylindrical opening 44 and may be sealed such as by being provided with an O-ring seal 47a. A rod or pin 48 projects from the piston into a receiving opening 49 in the block 46. When hydraulic fluid under pressure is admitted into the cylinder 44 behind the piston, it is pushed toward the block 46 to spread the ends of the brake and thereby release the brake.

For admitting hydraulic fluid behind the piston 47 a fitting 45 connects to a passage leading to the cylinder 44, and this fitting connects to the fluid delivery line 33, FIGURE 2, from the pump 30.

For normally maintaining the brake band 42 clamped around the surface of the tube 25, the brake applying means include headed pins or bolts 61 and 62 threaded into openings 72 and 73 in the block 43. The block 46 isslidable with respect to the bolts 61 and 62.

Surrounding the bolts are coil compression springs 63 and 64 which extend into recesses 66 and 67 in the block 46, and seat in the base 68 and 69 thereof to push the block 46 inwardly and tend to clamp the brake. The springs bear against a plate 65 on the bolts 61 and 62.

Slidable on the bolts are sleeves 7t) and 71 which are within the springs 63 and 64 and which limit the spreading movement of the ends 40 and 41 of the brake. At maximum spread position the bottoms 6S and 69 of the recesses 66 and 67 engage the ends of the sleeves 70 and 71.

A brake switch 50 is provided mounted on the block 46. The brake switch has a plunger 51 which is operated by a pin 52 adjustably mounted in the plate 65, as shown in FIGURES 3 and 4. When the brake is applied, the pin 52 releases the switch plunger 51, and when the brake is released, the pin 52 depresses the switch plunger 51.

The brake switch is shown in FIGURE 6 as connected into the circuit.

A feature of the invention resides in the relationship between the hydraulic force required to raise the piston 22 and the hydraulic force required to operate the brake piston 47. A lower hydraulic force is required for releasing the brake than for elevating the chair so that the brake will always be released before the chair is elevated. This will also always maintain the brake released due to the weight of the chair on the hydraulic fluid. In other words, the force of the hydraulic fluid in the chamber. 24- due to the force of the normal weight of the chair as indicated by the force arrow W is greater than the force required to spread the ends 40 and 41 of the brake. Thus, when the pump 30 is started and hydraulic pressure builds up the brake will be released before the chair starts to raise. This makes it possible for the chair operator, when the brake is on, to start the pump 30 only to release the brake, without elevating the chair.

The weight of the chair times the cross-sectional area of the piston 22 (which is the unit fluid pressure required to raise the chair) is greater than the force of the brake springs 63 and 64 divided by the cross-sectional area of the brake piston 44. For example, a preferred size relationship provides a lift piston 22 with an area of approximately 1 square inch with a chair having a weight of 150 pounds. In order to elevate the chair the pump will have to deliver fluid under pressure in excess of 150 pounds. The brake however is constructed to release at pounds fluid pressure. Various brake piston size and spring relationships may be employed, and a brake piston having an area of substantially 1.7 inches will operate at 140 pounds pressure against a brake applying spring resistance of 82 pounds.

FIGURES 6 and 7 show the circuit diagram for the mechanism. As illustrated in FIGURE 7, power is supplied from a line 56 which passes through a bulkhead 53 illustrated also generally in FIGURE 2 as forming the top of the reservoir. Thev lines lead upwardly within the tube 25 and connect to inechanism'which permits rotation and elevation of the chair to end in terminals on the chair plate 20 which are indicated by Roman numerals in FIGURE 7. These terminals connect to leads leading up to the chair with the terminals for the leads being numbered with Roman numerals corresponding to the connections indicated in FIGURE 7.

FIGURE 6 shows electrical outlets 59 and 60a on the right hand and let hand arms of the chair. The control arm 19 of FIGURE 1 may be connected to the switches or push button switches may be employed on the arm.

Power is obtained through a power line 56 of FIG- URE 7 and for convenience of reference the line 66 will be referred to as the power line or positive line and 67 will be referred to as the negative or ground.

For locking the chair against rotation or releasing it the lock switch 50a is operated. For moving the chair up or down the elevation control switch 57 isoperated.

When the chair is to be raised, as shown schematically in FIGURE 6, the switch arm 63 moves downwardly against the power contact 64 (which is connected to the power line 66 through terminal HI) and the switch contact 62 also moves against the power contact 65. The circuit of the contact 63 energizes terminal IV. This operates solenoid 58 to open its switch and break the circuit to the power outlets 59, and 69a by opening the ground line to terminal I. Thus, electrical appliances cannot be operated during the time the chair is being elevated. Terminal IV as shown in FIGURE 7 also energizes the motor start relay 55 through the brake switch 50, if the brake is locked. Energization through the brake 50 is only temporary however, since as soon as the motor 31 starts, hydraulic pressure will release the brake to depress the plunger of switch 50 and break the circuit from the terminal IV.

The principal circuit for operating the motor 31 to raise the chair is through the switch contact 62 which energizes the circuit through terminal VI to directly energize the relay 55, as shown in FIGURE 7.

If the chair is to be lowered, the terminal 6tl-of the switch 57 contacts the power contact 64 to energize the circuit through terminal VI. If the brake is unlocked the circuit to the motor relay 50 is broken. If the brake is locked, the circuit is completed to start the motor 31 and buildup hydraulic pressure to unlock the brake. As soon as the brake is unlocked, the switch 50 opens and the motor 31 stops (before the chair begins elevating inasmuch as the brake unlocks at a lower hydraulic pressure than required for elevating the chair).

As the switch 57 is operated in a down direction, the contact 61 is closed against the power contact 65 energizing the circuit V. The switch 50 will either be depressed because the brake is unlocked, or, as above described, the brake will immediately be unlocked through operation of the contact 60. With the switch 50 depressed, the circuit will be completed through the dumpvalve 36 to release fluid from beneath the piston 22 and,

permit the chair to descend. This will continue until the switch 57 is opened.

Locking or unlocking of the brake without elevation or lowering the chair is accomplished through the switch 50a, and if the ON contact is closed, the power circuit is completed through the terminal II to operate the lock valve 37 which releases fluid from within the brake cylin der 44 to apply the brake.

If the switch 50a is turned to the OFF position, this energizes the circuit through VI, which completes the circuit to the motor relay through the brake switch 50. However, as soon as the brake is released, the switch 50 will be opened to again stop the motor 31 so that the motor runs only long enough to release the brake.

In general operation, the operator raises the chair by operating the up switch which starts the motor 31 in FIGURE 2 to deliver hydraulic fluid to delivery lines 32 and 33. The brake 26 is released before the chair starts to ascend, inasmuch as the brake operates under a lower fluid pressure by design, than is required to raise the chair. For lowering the chair the operator manipulates the down switch which operates the oil release valve 36. The brake will remain released after an up or down operation since fluid will be trapped in the delivery line to the brake cylinder 44, FIGURE 5, by the check valve 35,

FIGURE 2.. For-locking or applying the brake, the lock switch is moved to a release position which opens the brake valve 37. The brake can be unlocked without raising the chair by operating the brake switch 50a which starts the motor 31 for very brief periods of time suflicient to build up enough pressure to unlock the brake without raising the chair.

Thus, it will be seen that I have provided an improved chair operating mechanism which meets the objectives and advantages above set forth. The mechanism eliminates unnecessary apparatus using the same hydraulic pump for chair elevation as brake operation, and provides a brake structure of simplified construction which is capable of a long operating life without attention.

The drawings and specification present a detailed disclosure of the preferred embodiments of the invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by the invention.

I claim as my invention:

1. A chair elevating mechanism for a rotary chair support comprising,

an elevating and support mechanism for the chair support including a piston and cylinder unit,

said mechanism including a vertical cylindrical braking surface movable with the chair support,

a fluid pump having a discharge connected to said piston and cylinder unit for delivering fluid under pressure to the unit for elevating the chair support,

a break member engageable with said braking surface to selectively lock the vertical position of the chair support and movable between locked and release positions,

biasing means normally holding the brake member in locked position,

a fluid powered brake operator for moving said brake member to release position,

and means connecting said pump discharge to said brake operator so that the brake is automatically released simultaneously with operation of the pump and prior to elevation of the chair support.

2. A chair elevating mechanism for a rotary chair support comprising,

a base,

a fluid piston and cylinder unit on the base supporting said chair support for raising or lowering the chair support,

a fluid pump having a discharge connected to said unit 6 for delivering fluid under pressure to said unit for elevating the chair support,

a brake for locking the position of the chair support,

a fluid powered brake operator for releasing said brake,

and means connecting said pump discharge to said brake operator so that the brake is automatically released simultaneously with operation of the pump.

3. A chair elevating mechanism for a rotary chair support comprising,

a base,

a fluid powered elevating mechanism for elevating the chair support,

a fluid pressure delivery means connected to said elevating mechanism,

a brake for locking the position of the chair support having a normally locked condition,

a fluid powered brake operator for releasing said brake,

and means connecting said fluid pressure delivery means to said brake operator for releasing the brake with operation of said fluid powered elevating mechanism.

4. A chair elevating mechanism for a rotary chair support comprising,

abase,

a vertical cylinder mounted on the base,

a piston within the cylinder supportingly connected to the chair support,

a dowwardly extending tube secured to the chair support having an outer cylindrical surface,

a brake band surrounding said tube and secured to the base,

a spring urging said band to clamp around the tube and lock the tube,

a fluid powered brake operator connected to the band for opening the band for releasing the tube,

a fluid pump having a discharge connected to the cylinder for delivering fluid under pressure for elevating the chair support,

and means connecting said pump discharge to said brake operator so that the brake is automatically released simultaneously with elevation of the chair support.

5. A chair elevating mechanism for a rotary chair support comprising,

a base,

a vertical cylinder mounted on the base,

a piston within the cylinder supportingly connected to the chair support,

a downwardly extending tube surrounding said cylinder and secured to the chair support having an outer cylindrical surface,

a brake band wrapped around the tube having spreadable ends,

spring means holding the ends together for locking the band,

a brake cylinder on one of said ends,

a brake piston in the brake cylinder connected to the other end for releasing the band,

a fluid pump having a discharge connected to said cylinders for delivering fluid under pressure for elevating the chair support and releasing said brake,

and release means connected to said cylinders for lowering the chair support and releasing said brake.

6. A chair elevating mechanism between a chair base and a chair support comprising a piston and cylinder unit and including a vertical cylindrical braking surface mova ble with the chair,

a brake having a band engageable with said surface for locking the position of the chair support and having separable ends,

biasing means connected to said ends for holding said brake locked,

a cylinder formed in one of said ends,

a piston slidable in said cylinder and connected to the other end for releasing said brake,

a hydraulic pump having a discharge connected to said 7 cylinder unit and said brake cylinder for simultaneously elevating the chair support and releasing the brake,

and fluid release valve means connected to said cylinder unit and said brake cylinder for simultaneously lowering the chair support and releasing the brake.

7. A chair elevating mechanism for a rotary chair support being positioned between a base and the rotary support comprising, a piston and cylinder unit and including a vertical cylindrical braking surface movable with the chair support,

a brake having a band engageable with said surface for locking the position of the chair support and having separable ends,

biasing means connected to said ends for holding said brake locked,

a cylinder formed in one of said ends,

a piston slidable in said cylinder and connected to the other end for releasing said brake,

means limiting the spreading of the ends of the hand against action of the piston,

a hydraulic pump having a discharge connected to said cylinder and to said brake cylinder for simultaneous- 1y elevating the chair support and releasing said brake,

first valve means connected to said cylinder unit,

second valve means connected to said brake cylinder,

and means for simultaneously operating said first and second valve means so that the brake will be released when the chair is lowered.

8. A chair supported elevating mechanism between a base and chair including, a piston and cylinder unit and including a vertical cylindrical braking surface movable with the chair,

a brake having a band engageable with said surface for locking the position of the chair and having separable ends,

a cylinder formed in one of said ends,

a piston slidable in said cylinder and connected to the other end for releasing said brake,

a pin secured to the first of said ends and slidable relative to the second end and having a head,

a compression spring on the pin acting between said head and said second end for clamping the band to the surface,

a stop on the pin engageable by the second end limiting spreading of the ends,

a hydraulic pump having a discharge connected to said cylinder unit and said brake cylinder for simultaneously elevating the chair and releasing said brake,

and fluid release valve means connected to said cylinder unit and said brake cylinderfor simultaneously lowering the chair and releasing the brake.

9. A chair supported elevating mechanism between a base and chair including, a piston and cylinder unit and including a vertical cylindrical braking surface movable with the chair,

a brake having a band engageable with said surface for locking the position of the chair and having separable ends,

a cylinder on one of said ends,

a piston slidable in said cylinder and connected to the other end for releasing said brake,

a hydraulic pump having a discharge connected to said cylinder unit and said brake cylinder for simultaneously elevating the chair and releasing said brake,

fluid release valve means connected to said cylinder unit and said brake cylinder .for simultaneously lowering the chair and releasing the brake,

and means for spreading said ends to release said brake with release of pressure in said brake cylinder including a pair of beaded pins threaded into the first of said ends and slidable with respect to the second end,

coil compression springs on said pins acting between the heads and the second ends urging the ends together for clamping the brake band around the braking surface,

and stop sleeves shorter than the pins mounted thereon and engageable by the second end of the band at a position where the band is released and limiting the separation of the second end of the band from the first end.

References Cited by the Examiner UNITED STATES PATENTS 1,534,790 4/1925 Koken 297347 1,853,096 4/1932 Stukenborg 52 2,323,519 7/1943 Dean.

2,372,196 3/1945 Grime 18867 2,653,648 9/ 1953 Marshall 297347 2,851,995 9/1958 Westcott 9226 2,854,061 9/1958 Romito 6052 X 2,969,772 1/ 1961 Cahill 9l44 JULIUS E. WEST, Primary Examiner. 

3. A CHAIR ELEVATING MECHANISM FOR A ROTARY CHAIR SUPPORT COMPRISING, A BASE, A FLUID POWERED ELEVATING MECHANISM FOR ELEVATING THE CHAIR SUPPORT, A FLUID PRESSURE DELIVERY MEANS CONNECTED TO SAID ELEVATING MECHANISM, A BRAKE FOR LOCKING THE POSITION OF THE CHAIR SUPPORT HAVING A NORMALLY LOCKED CONDITION, A FLUID POWERED BRAKE OPERATOR FOR RELEASING SAID BRAKE, AND MEANS CONNECTING SAID FLUID PRESSURE DELIVERY MEANS TO SAID BRAKE OPERATOR FOR RELEASING THE BRAKE WITH OPERATION OF SAID FLUID POWERED ELEVATING MECHANISM. 